I like the idea of this little cheap valve head that can be modified in a virtually endless amount of ways, but is it possible to mod it for a sh*tload more distortion?

I'm not into metal to a great extent but it's nice to have that bit of extra distortion/volume on demand for some very fast and technique orientated solos.

So if it is possible, without pedals/FX etc. might I add, how does one go about doing it?